Same as Pan's pipes (which see, under pipe).In Egypt. archæol., a narrow and deep rock-cut channel or tunnel forming a characteristic feature of Egyptian tombs of the New Empire.In anatomy, the Eustachian tube.In ornithology, the voice-organ of birds; the lower larynx, situated at or near the bifurcation of the trachea into the bronchi, and serving to modulate the voice, as in singing.In surgery, a fistula.n. In some of the brachiopods, like Syringothyris, a split tubular structure developed from the deltidial plates, lying within the umbonal region of the ventral valve, and inclosing or forming a passage for the pedicle.